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Re: [TLS] simplistic renego protection

"Blumenthal, Uri - 0662 - MITLL" <uri@ll.mit.edu> Tue, 17 November 2009 17:08 UTC

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From: "Blumenthal, Uri - 0662 - MITLL" <uri@ll.mit.edu>
To: "tls@ietf.org" <tls@ietf.org>
Date: Tue, 17 Nov 2009 11:44:52 -0500
Thread-Topic: [TLS] simplistic renego protection
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Subject: Re: [TLS] simplistic renego protection
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On 11/17/09  11:38 , "Nasko Oskov" <noskov@microsoft.com> wrote:

> Michael D'Errico wrote:
>> ........You just need three things:
>> 
>>   1) a client-to-server signal
>>   2) a server-to-client signal
>>   3) somehow incorporate the previous verify_data in the handshake
> 
> It was indicated that some implementations use random value for the
> timestamp part of the random values exchanged. If this is correct and there
> are no interop issues with it, then we can use the timestamp as place to
> include a few bits as well.

>From cryptographic point of view I hate seeing "timestamp" part of a random
value filled with yet another random. If your [P]RNG quality is less than
perfect you're seeking trouble.  (And if your RNG is perfect - why did you
need to put a timestamp there anyway?)
-- 
Regards,
Uri
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